Apparatus for distilling oils



Nov. 7, 1933. J. E. scHuLzE APPARATUS FOR DISTILLING OILS Original Filed March 18 1922 Aww, NK,

Num @w m bw mm @m MUN ,mm Www QN NN( Patented Nov. 7, 1933 1,934,150 l APPARATUS Fon DIs'rILLlive.v orLs John E. Schulze, Chicago, 111., assignor'to Red River Refining Company, Inc., Shreveport, La., a corporation of Louisiana original application March' 1s, i922, serial No. 544,931, now Patent No.V 1,448,709.` Divided and this application February 15, 1923;

Serial No.V 619,256. Renewed August 14, 1930" 3 Claims.,. (Cl. 196.--114) This invention relates to apparatus for. distilling oils; and it relates more particularly (to apparatus that can be used with advantage in practicing the low-pressure distillation process 5 of my prior application Serial No. 544,931, led March 18, 1922, (Patent No. 1,448,709, March 13,

1923 Vof which the present application is a di' vision. n

The process disclosed and claimed in said prior application is characterized by distillation of mineral oil material, either with or Without the aid of superheated steam, at absolute pressures of 25 millimeters mercuryA or less, most desirably at or below 5 millimeters.` Incarrying out a process of this type, it is important that the still and associated apparatus employed therewith be of such character that the Whole system-can be kept under the desired low pressure clear through to and including the receiving tanks. This requires that the apparatus be so constructed that all leaks are avoided. It is also important that the vapor otake means leading fromthe distilling apparatus vto the condensing system be of such ample cross sectional area, and that it be so designed and constructed, that the vapors arising from the body of oil undergoing distillation can pass freely out of the still to the condenser in the minimum amount of time and with the minimumobstruction.v Care should be taken particularlyto avoid as far as is practicable the reluxing of any condensed vapors back into the still. In other Words, cracking in the ordinary sense of the word, Whether by refluxing or otherwise, is to be avoided as far as possible in carrying out the novel process. In some embodiments oi the invention steam is employed to assist the distillation, and inthat case the apparatusV used should include provision `for supplying steam under such control as nevertheless to permit operation at the desired low "pressure.

It is a principal object of the inventionl to provide apparatus that meets theforegoing requirements in a practical manner and is at the 5 same time relativelysimple in construction and arrangement.

With this general object in view, as Well as others which will become apparent hereinafter, the invention comprises the novel apparatus parts and combinations thereof which will first be described in connection with a typicalillustrative embodiment of apparatus Within the scope of the invention, and will then be' more particularly pointed out in the claims.

One practical form of apparatus in which the novel process may be carried out is shown in the accompanying drawing which illustrates, more or less diagrammatically, a complete Working system in elevation, parts being in section for clearness oi' illustration. This system is adapted for distillation either with or Without the use of steam.

At l() is a horizontal cylindrical still internally strengthened in any suitable manner to prevent collapse, as by means of peripheral ribs V1l and diametrical braces 12; the peripheral ribs 11 being apertured or interrupted at the bottom of the still, as' indicated at 13, in order not to obstruct free movement of liquidv material valong the bottom. Vapors from the still 10, after pass'- ing the baie 14 guarding the vapor outlet of the still, go through large vapor oitake pipe`15 to a condenser coil 16 contained in a condenserbox 17, which is provided with a pipe 18 for admis,- sion of steam 'or other fluid heating agent to Warm the coil 16 Where desirable, and with an overflow pipe 19. Said baffle 14 should be positioned far enough below the vapor outletl to avoid materially restrictingthe outow of vapors Aor causing refluxing to the still. The condenser coil 16 discharges into a closed baiile box or separator 20 at a point below the'topthereof, said box or separator. containing a series of baflles indicated at 20a, and vhaving a liquiddischarge pipe 21 leading from the lower part thereof, and a'vapor oiftakepipe 22 leading from the upper part thereof. The liquid discharge pipe 21 goes through a look bo`x'23, and thence into a manifold or header.` 24 which communicates by branches 25, through valves 26, withV receivers Y27.

Vapor offtake pipe 2 2 goes to a condenser coil 28 immersed in a cooling liquid contained inl box 29, said coil 28 discharging into the receiving tank 30, having a valved draw-01T pipe 31 and a pipev connection 32` leading from the up- .per partici" the ltank to the main vacuum pump P1, which should be capable of maintaining Ya diminished pressure of as low as 1.0 or 1.5mm of mercury in-the entireY system. Means are provided` to cool the condenser 28 and receiver 30, when these are employed, such means taking the form in'this instance of afrefrigerating sys-l tem inr which cooling brine is suppliedgfroma suitablevbrine pump (not shown) through Vpipe 33 to -coil 34 inlthe receiver, andthence to coil 35 in the condenser box 29, the brine returning tothe brine tank (not shown)Y through pipe'36.` When steam or water vapor is to be used in the distillatiomthis is furnished by a'boiler 3-7 pro-f vided with ableederl valve 38, and witha vapor 110 exit pipe 39 leading to a coil 40 arranged in a superheater 41, said coil 40 discharging through pipe 42 past valve 43 into the still 10. Said discharge pipe 42 extends well toward the bottom of the still and has its lower part 42HL perforated for delivery of the superheated steam or Water vapor in jets into the still contents.

In order to permit rapidly withdrawing samples of the oil distillate for test as the distillation progresses, without admitting any substantial quantity of air into the system, a sampling device is provided comprising a small closed containeror chamber 44 connected to header 24 by an inilow pipe connection 45 valved at 46, and having a discharge 47 valved at 48. Said chamber is also provided with a bleeder valve 49, opening to atmosphere. With valve 46 open and valves 48, 49 closed, distillate flows into and iills container 44. Upon closing valve 46 and opening valves 48, 49, the distillate in the container is discharged under atmospheric pressure. The valves are then restored to their first mentloned positions. The sampling container is of suchvsmall size as compared to the'rest of the apparatus, that the quantity of air `admitted into the container at each sampling is negligible as regards its effect on the system or on the oil therein. It is to be noted that admission of any substantial quantity of air into the system is to be guarded against, not only because of the consequent difliculty of maintaining the desired high degree of vacuum, but also because of the `oxidizing effect on the oil. Substantial oxidation Wouldseriously impair effective operation of the process 'or even defeat it altogether.

Assuming the 'distillation of oil under high vacuu'm'and with the use of water vapor introduced into the still, the still 10 ris charged with oil, `such as topped crude or residuum, up to approximately the level indicated in dotted lines, and the vacuum pump P1 connected with pipe 32 is started, valves 29a, 32a and 32b being open, and valves 52, '53 being closed. Heat is applied to still 10 and superheater 41. If the atmospheric temperature is suiciently low to require it, heat is also applied at the same time to water boiler 37to generate water vapor. Valve 43, which has been closed up to this time, is now opened slightly and the Vbrine pump is started to supply brine through pipe 33 to the refrigerating coils 34 and 35 for cooling the condenser 28-29 and receiving tank 30. SteamV may be run into condenser box 17 through pipe 18 in order to keep the condenser 16-17 warm enough to prevent condensation of moisture and yet to ensure vcondensation of the oil vapors coming over from the still 10. Water resulting from the condensation of steam in 17 overflows at 19. The admission of steam is so controlled by valve 43 as to permit the vacuum pump P1 to maintain an absolute pressure of not more than 5 mm. mercury in the system.

When the condensed oil and uncondensed Water vapor reach the baffle box or separator 20, they separate, the water vapor passing out through the offtake 22 and thence into the cold condenser 28-29 Where it condenseathe resultant Water collecting in receiving tank l30. The Water vapor is accompanied by Volatile' matter which if not separated from the condensed oil would be absorbed by the latter 'upon cooling and would contaminate the same. 'The condensed oil, on the other hand, nows down by gravity through thelseparator 20 andpasses to y thesight box 23, going thence into whichever one of the receivers 27 is at that time open to the header 24. Thus the water and oil are collected entirely separately and the formation of emulsions is prevented.

YWhen the distillation is completed, valve 43 is closed and bleeder valve 38 opened to establish atmospheric pressure in the boiler. This preventsthe oil or residue siphoning back from still 10 into boiler 37. The main vacuum pump Pi is then shut down, and the bleeder valve 50 of the connected receiver 27 is opened to bring the system back to atmospheric pressure. Steam is cut off1 from condenser box 17 and the brine pump is shut down. Water is then drained from receiving box 30 through drain pipe 31. The liquid residue in still 10 may be run off through a suitable drain pipe (not shown), the entire residue being easily removed because of the entire absence of coke. The operation is thus completed and the apparatus is ready for another run.

In employing the described apparatus for carrying out the process of the invention where water vapor is not used in conjunction with the high vacuum, the baille box 20 and the parts in series therewith through `vapor outlet pipe 22 are not required, and the intake of main vacuum pump P1 is connected directly to vapor outlet 22 through pipe 51 by opening valves 52, 53, While valves 29*a and 32a are now closed. It is of course also unnecessary to employ the steam generating system, and valve 43 therefore remains closed when employing dry distillation. Ordinarily it is also unnecessary to admit steam to the condenser tank 17; and where desirable, a cooling fluid may even be admitted thereto through pipe 18.

Pipes 54, connected with an auxiliary vacuum pump P2 through header 55, enable restoration of low pressure in either receiver 27, after withdrawal of the condensed distillate therefrom, without disturbing the pressure in the system or admitting air thereinto. When a receiver 27 is filled, its admission valve 26 is closed, air is admitted through bleeder valve 50, valve 57 of discharge pipe 58 is opened, and the distillate is pumped to storage tanks (not shown). When the receiving tank is empty, valves' 57 and 50 are closed, the auxiliary vacuum pump P2 connected to pipe 54 is started, and valve 56 in pipe 54 is opened; and when the desired reduction inV pressure has been reached, valve 56 is closed and valve 26 is opened, the main vacuum pump P1 thereafter acting to maintain the desired degree of vacuum in the receiver as well as in the other parts of the system.

While a specific embodiment of apparatus well adapted for 'practical use has been described hereinabove for the sake of a concrete example in order to illustrate the principles of the invention, it will be understood that the invention is not limited thereto but is susceptible of considerable modification in detail and arrangement of parts While still realizing the benets of the invention to a substantial extent.

What I claim is:

1. Apparatus for distilling oil comprising the combination,`with astill and means for introducing steam thereinto, of condenser means connected to said still and arranged to condense Y oil vapors receivedtherefrom without condensing water vapor, a separator into which condensed oil and uncondensedl water vapor pass from said'condenser means, a receiver into which condensed oil is discharged from said separator,

condenser means into which pass vapors from said separator, and a vacuum pump having its intake connected to the last mentioned condenser means, said vacuum pump intake being also connected directly to said separator, whereby said pump can exhaust the system either directly through said separator or through the interposed condenser means, as may be desired.

2. Apparatus as set -iorth in claim 1 further characterized by the provision of refrigerating means to cool the condensing means receiving vapor from said separator.

3. Apparatus for distilling lubricating oil com-v prising the combination, with` a still, means for introducing steam thereinto, a hot condenser into which mixed lubricating oil vapors and 

